Accumulated tidal heating of stars over multiple pericentre passages near SgrA*

Abstract

We consider the long-term tidal heating of a star by the supermassive black hole at the Galactic centre, SgrA*. We show that gravitational interaction with background stars leads to a linear growth of the tidal excitation energy with the number of pericentre passages near SgrA*. The accumulated heat deposited by excitation of modes within the star over many pericentre passages can lead to a runaway disruption of the star at a pericentre distance that is four to five times farther than the standard tidal disruption radius. The accumulated heating may explain the lack of massive (greater than or similar to 10M(circle dot)) S-stars closer than several tens of au from SgrA*.